Un Mésosuchien ziphodonte dans l'Éocène supérieurde La Livinière (Hérault,France)

Crocodilian remains collected at the turn of the centuryin the early Bartonian locality of La Livinière (Hérault, southern France) belong to a ziphodont mesosuchian. They include compressed, serrated teeth, primitive jugals, amphicoelous vertebrae, dermal scutes, and elongated, slender limb bones. The systematic position of this animal is difficult to determine, but it is more reminiscent of some forms from the upper Cretaceous of South America than of the Tertiary Sebecidae. It may be related to Iberosuchus, a ziphodont mesosuchian from the Eocene of the Iberian peninsula. Its peculiar limb bones confirm the terrestrial habits of ziphodont crocodilians.     

Late Cretaceous crocodile remains from Naskal (India): comparisons and biogeographic affinities

Crocodile teeth from the Maastrichtian inter-trappean beds of Naskal (peninsular India) are described here. Because of isolated denticles visible on sufficiently preserved carinae, the presence of a strong heterodonty (in size and shape), and by comparison to crocodile teeth from various taxa, they are considered as representing a ziphodont form with a heterodont dentition. The difference between ziphodont, “false ziphodont” and non-ziphodont dentitions is evaluated. With the help of scanning electron microscope photographs, it is shown that only precise characteristics of the denticles and not the tooth shape, allow to distinguish the three categories. These three categories do not correspond to monophyletic groups. It is also shown that the “alligatorid” heterodonty, meso- or eusuchian in grade, exists in each category. Although the ziphodont dentition is not sufficient to allow a taxonomical definition, the peculiarities that it often presents, depending on the taxa as well as the teeth shape, enable systematic approaches. An examination of previous works on the possible ziphodont crocodiles from the Tertiary deposits of the Indian subcontinent and on Naskal teeth demonstrate that the latter are closer to those of some Gondwanan crocodiles of mesosuchian grade, known from the early Cretaceous of Africa and possibly a form from the late Cretaceous of Madagascar. They are excluded from eusuchian Laurasiatic as well as Paleogene forms of the Indian subcontinent, either ziphodont or not. Contrary to the earlier works on the inter-trappean crocodiles, the present study removes this group as one of the evidences in support of an early (late Cretaceous-early Tertiary) India/Asia collision model. In fact, it provides an additional support for the existence of possible Cretaceous biogeographic links between India, Madagascar, Africa, and South America.     

Paratritemnodon indicus (Creodonta: Mammalia) from the early Middle Eocene Subathu Formation,NW Himalaya,India, and the Kalakot mammalian community structure

A complete post-incisor upper dentition and a left mandible with P/3-M/3 of the proviverrine hyaenodontid (Creodonta: Mammalia)Paratritemnodon indicus, which was hitherto known by heavily worn P/3-M/3, are described from the uppermost Subathu Formation (Middle Eocene) of the Kalakot-Metka-Mohgala area, Rajauri District, Jammu and Kashmir.P. indicus is most closely related to the North American Early Eocene proviverrine,Tritemnodon; its relationships withProdissopsalis from the Middle Eocene of Europe andPropterodon from the Middle to Late Eocene of China are also close. In the Kalakot Eocene vertebrate community of the Subathu vertebrate bioprovince,P. indicus is the only land dwelling carnivorous mammal against more than 20 species of herbivorous mammals, a majority of which are larger than it. This is viewed as an imbalance in trie community and it reflects an immaturity of the ecosystem supporting the fauna. The scarcity of carnivore remains in the Kalakot mammalian fauna is not an artifact.     

Crocodylian assemblage from the middle Eocene Ikovo locality (Lugansk Province,Ukraine), with a discussion of the fossil record and geographic origins of crocodyliform fauna in the Paleogene of Europe

The known fossil record of crocodyliforms in Europe during the Paleogene is significantly biased, in that the fauna of Western Europe is far better sampled and understood compared to that of Eastern Europe. We describe in detail all known crocodyliform remains from the middle Eocene (Lutetian) Ikovo locality in Ukraine. We conclude that at least two taxa were present: a moderate to large-sized Tomistominae indet. similar to the basalmost known tomistomines, and the small-sized basal alligatoroid cf. Diplocynodon sp. Despite its scarcity, this is the first basal alligatoroid material reported from Eastern Europe (as part of post-Soviet countries) and the easternmost record of diplocynodontines in Europe so far. An allegedly freshwater cf. Diplocynodon sp. contributes a rare faunal element to the vertebrate assemblage of the Ikovo locality, otherwise dominated by resident or facultative marine taxa. The fossil record and historical paleobiogeography of crocodyliforms from the Paleocene and Eocene of Europe are reviewed. As it has been already known, the middle Eocene fauna of crocodyliforms proves to be taxonomically diverse and complex. Its constituent lineages geographically originated in Asia or North America (Diplocynodontinae, Asiatosuchus-like crocodyloids, Planocraniidae), North America (derived alligatorines), Africa (Tomistominae), and Gondwana (ziphodont mesoeucrocodylians Iberosuchus and Bergisuchus), with possible subsequent speciation in Europe. We propose a novel hypothesis of Asian origins of European diplocynodontines, which will be explicitly tested in future studies. The revealed similarities between crocodylians and turtles from the Ikovo locality and those from Western Europe support the presence of a single Pan-European biogeographical zone during the middle Eocene, distinct from that of Asia.     

Crocodiles in the Sahara desert: an update of distribution, habitats and population status for conservation planning in Mauritania

Background

Relict populations of Crocodylus niloticus persist in Chad, Egypt and Mauritania. Although crocodiles were widespread throughout the Sahara until the early 20^th century, increased aridity combined with human persecution led to local extinction. Knowledge on distribution, occupied habitats, population size and prey availability is scarce in most populations. This study evaluates the status of Saharan crocodiles and provides new data for Mauritania to assist conservation planning.

Methodology/Principal Findings

A series of surveys in Mauritania detected crocodile presence in 78 localities dispersed across 10 river basins and most tended to be isolated within river basins. Permanent gueltas and seasonal tâmoûrts were the most common occupied habitats. Crocodile encounters ranged from one to more than 20 individuals, but in most localities less than five crocodiles were observed. Larger numbers were observed after the rainy season and during night sampling. Crocodiles were found dead in between water points along dry river-beds suggesting the occurrence of dispersal.

Conclusion/Significance

Research priorities in Chad and Egypt should focus on quantifying population size and pressures exerted on habitats. The present study increased in by 35% the number of known crocodile localities in Mauritania. Gueltas are crucial for the persistence of mountain populations. Oscillations in water availability throughout the year and the small dimensions of gueltas affect biological traits, including activity and body size. Studies are needed to understand adaptation traits of desert populations. Molecular analyses are needed to quantify genetic variability, population sub-structuring and effective population size, and detect the occurrence of gene flow. Monitoring is needed to detect demographical and genetical trends in completely isolated populations. Crocodiles are apparently vulnerable during dispersal events. Awareness campaigns focusing on the vulnerability and relict value of crocodiles should be implemented. Classification of Mauritanian mountains as protected areas should be prioritised.     

A new stratigraphic occurrence of the taxon Pagetia (Trilobita) from the Spiti region and its biostratigraphic significance in correlation of the Wuliuan Stage (Miaolingian Series) in the Kashmir and the Spiti regions (Tethyan Himalaya), India

Abundant, though moderately well-preserved, specimens of Pagetia sp. are recorded along with the ptychopariid Xingrenaspis dardapurensis from a new stratigraphic level which lies above the Oryctocephalus salteri biozone in the Spiti region (Himalaya). This occurrence of Pagetia in a higher stratigraphic level (higher than the Oryctocephalus salteri biozone) from the Spiti region helps in understanding the distribution of this taxon in the Cambrian of the Kashmir and Spiti regions of the Himalaya. A Pagetia-Xingrenaspis association from the Kashmir region is already known, the present discovery of a similar association in the Spiti region enables the Wuliuan (Miaolingian) biostratigraphic correlation between the Kashmir and the Spiti regions. The record of the taxon Pagetia from a higher stratigraphic level in the Spiti region contradicts the previous assumption that the Pagetia bearing level in Kashmir is equivalent to the Pagetia-Oryctocephalus indicus (O. indicus biozone, Hayden horizon 2) in the lowest part of the Wuliuan in the Spiti region.     

Fruits of Wetherellia and Palaeowetherellia (?Euphorbiaceae) from Eocene sediments in Virginia and Maryland

The Eocene sediments of southern Maryland and adjacent Virginia have yielded multilocular fruits assignable to the extinct generaWetherellia Bowerbank andPalaeowetherellia Chandler. This is the first report of their co-occurrence in one deposit.Wetherellia has previously been reported from the Eocene of southern England and West Germany (two species), whilePalaeowetherellia has been reported from the Eocene and possibly latest Cretaceous of Egypt (one species). APalaeowetherellia-like fruit has been reported from the Eocene of southeastern North America.Wetherellia marylandica comb. nov. andPalaeowetherellia species are described; new information is provided for the previously established speciesWetherellia variabilis andW. dixonii. The familial assignment of both genera is reviewed.Palaeowetherellia is most similar to fruits of the tribe Hippomaneae of the Euphorbiaceae, whileWetherellia finds counterparts in the Euphorbiaceae and the Meliaceae. While the exact affinities ofWetherellia are difficult to resolve through comparison to modern fruits, the similarity ofWetherellia andPalaeowetherellia might suggest that the former is more likely euphorbiaceous than meliaceous. The discovery of these New World members of both genera reinforces the importance of floristic exchange across the North Atlantic in earliest Tertiary time.     

A new basal raoellid artiodactyl (Mammalia) from the middle Eocene Subathu Group of Rajouri District,Jammu and Kashmir,northwest Himalaya,India

A new artiodactyl of moderate size, Rajouria gunnelli nov. gen., nov. sp., is described on the basis of several dentaries, maxillae and isolated teeth from the middle Eocene Subathu Group of the Kalakot area, Rajouri District, Jammu and Kashmir, India. Despite its general resemblance with the family Dichobunidae by the retention of a paraconid on m1-2 and a simple P4 where endocristids do not form an anterior loph, this taxon shares with Raoellidae two unambiguous characters: the presence of a hypoconid on p4, and an asymmetrical P4. The phylogenetic position of the new taxon within the Cetacea–Raoellidae clade is strongly supported by seven non ambiguous synapomorphies, among which a cristid obliqua on lower molars anteriorly pointing towards the postectoprotocristid, and a P3 with only two roots. The presence of a new basal raoellid in the middle Eocene Subathu Group sheds new light on the phylogeny and paleobiogeography of raoellid artiodactyls.     

A new tarkadectine primate from the Eocene of Inner Mongolia,China: phylogenetic and biogeographic implications

Tarka and Tarkadectes are Middle Eocene mammals known only from the Rocky Mountains region of North America. Previous work has suggested that they are members of the Plagiomenidae, an extinct family often included in the order Dermoptera. Here we describe a new primate, Tarkops mckennai gen. et sp. nov., from the early Middle Eocene Irdinmanha Formation of Inner Mongolia, China. The new taxon is particularly similar to Tarka and Tarkadectes, but it also displays many features observed in omomyids. A phylogenetic analysis based on a data matrix including 59 taxa and 444 dental characters suggests that Tarkops, Tarka and Tarkadectes form a monophyletic group—the Tarkadectinae—that is nested within the omomyid clade. Within Omomyidae, tarkadectines appear to be closely related to Macrotarsius. Dermoptera, including extant and extinct flying lemurs and plagiomenids, is recognized as a clade nesting within the polyphyletic group of plesiadapiforms, therefore supporting the previous suggestion that the relationship between dermopterans and primates is as close as that between plesiadapiforms and primates. The distribution of tarkadectine primates on both sides of the Pacific Ocean basin suggests that palaeoenvironmental conditions appropriate to sustain primates occurred across a vast expanse of Asia and North America during the Middle Eocene.     

First Record of Eocene Bony Fishes and Crocodyliforms from Canada’s Western Arctic

Background

Discovery of Eocene non-marine vertebrates, including crocodylians, turtles, bony fishes, and mammals in Canada’s High Arctic was a critical paleontological contribution of the last century because it indicated that this region of the Arctic had been mild, temperate, and ice-free during the early – middle Eocene (∼53–50 Ma), despite being well above the Arctic Circle. To date, these discoveries have been restricted to Canada’s easternmost Arctic – Ellesmere and Axel Heiberg Islands (Nunavut). Although temporally correlative strata crop out over 1,000 km west, on Canada’s westernmost Arctic Island – Banks Island, Northwest Territories – they have been interpreted as predominantly marine. We document the first Eocene bony fish and crocodyliform fossils from Banks Island.

Principal Findings

We describe fossils of bony fishes, including lepisosteid (Atractosteus), esocid (pike), and amiid, and a crocodyliform, from lower – middle Eocene strata of the Cyclic Member, Eureka Sound Formation within Aulavik National Park (∼76°N. paleolat.). Palynology suggests the sediments are late early to middle Eocene in age, and likely spanned the Early Eocene Climatic Optimum (EECO).

Conclusions/Significance

These fossils extend the geographic range of Eocene Arctic lepisosteids, esocids, amiids, and crocodyliforms west by approximately 40° of longitude or ∼1100 km. The low diversity bony fish fauna, at least at the family level, is essentially identical on Ellesmere and Banks Islands, suggesting a pan-High Arctic bony fish fauna of relatively basal groups around the margin of the Eocene Arctic Ocean. From a paleoclimatic perspective, presence of a crocodyliform, gar and amiid fishes on northern Banks provides further evidence that mild, year-round temperatures extended across the Canadian Arctic during early – middle Eocene time. Additionally, the Banks Island crocodyliform is consistent with the phylogenetic hypothesis of a Paleogene divergence time between the two extant alligatorid lineages Alligator mississippiensis and A. sinensis, and high-latitude dispersal across Beringia.     

Body temperature and basking behaviour of Nile crocodiles (Crocodylus niloticus) during winter

The ability to thermoregulate in reptilians is often through behavioural modification. We investigated body temperature (T_b) patterns during winter in the amphibious Nile crocodile (Crocodylus niloticus) and its relationship to basking behaviour at the St. Lucia Crocodile Centre, St. Lucia, South Africa. It was found that crocodiles had no daily plateaus in T_b but rather continuous oscillations in T_b within a range of mean minimum T_b 18.8–19.6 °C to mean maximum T_b 26.9–29.2 °C. Crocodile T_b increased during the day, usually after 10:00 irrespective of body size. Behavioural data showed that the crocodiles usually left the water to bask around 10:00. It is suggested that basking behaviour is important for elevating T_b rather than attaining a preferred T_b. The increased T_b may allow them to perform optimally when they return to water. The basking occurrence has management implications as it suggests that the best time to conduct aerial censuses of the St. Lucia crocodiles is during winter after 10:00 when most of the individuals are basking and hence most easily seen.     

河南淅川核桃园组的低等四足类动物群

<正> Since 1920's, abundant fossil mammals have been collected from the Middle Eocene Hetaoyuan Formation, Xichan, Henan Province. On the contrary, only two reptile remains from these continental deposits have been reported——a turtle, Sinohadrianus sichuanensis Ping, 1929, and a crocodile Pristichampsus aff. P. rollinati identified on the basis of several ziphodont teeth (Chow et al., 1973).     

Effect of human-mediated migration and hybridization on the recovery of the American crocodile in Florida (USA)

The American crocodile (Crocodylus acutus) is a large apex predator with an extensive but fragmented range. Crocodylus acutus suffered a population crash and was almost extirpated from Florida (USA) during the 1970s; however, in 2007 it was federally downlisted from endangered to threatened based on an increase of suitable habitat and a growing population. A genetic assessment of this population has not been performed even though foreign crocodiles have been released into Florida waters. Herein, we use mitochondrial and nuclear DNA markers to characterize relationships among American crocodiles along the southern coast of Florida and reference samples from other countries. We detected inter- and intra-specific hybridization and unexpected population structure attributed to human-mediated migration of crocodiles from Latin America and the Greater Antilles. Our results suggest that the population size of crocodiles actually native to Florida should be reevaluated, particularly in light of ongoing admixture in this population. We reemphasize the utility of genetic markers in conservation and management programs for endangered species; especially those that can hybridize with closely related congeners. The American crocodile in Florida has recovered owing to successful conservation initiatives, but a long-term management protocol that takes genetic data into account is still needed.     

Ethnobotanical and antibacterial study of Primula plants traditionally used in the indigenous communities of Western Himalaya,Pakistan

BackgroundThe upper belt of Azad Kashmir is a hilly, mountainous, and remote area where the indigenous communities mainly believe in traditional medicines for the treatment of different ailments. This study aimed to conserve scientifically and culturally important medicinal knowledge of Primula species in Azad Kashmir, Western Himalaya, Pakistan. The additional objective was to evaluate the antibacterial activity of these plants against pathogenic bacteria.MethodsThe ethnomedicinal data of Primula species was explored by conducting structured interviews with 40 informants of the study area, especially asking about the medicinal uses of Primula species. The indigenously used Primula species were further analyzed for their antibacterial activity against both gram-positive and gram-negative bacteria by using disc diffusion assay supplemented with a more robust minimum inhibitory concentration assay.ResultsEthnomedicinal data revealed that indigenous communities living in upper regions of Azad Kashmir use 5 Primula species for the treatment of various disorders. The highly cited disease category was ophthalmic disorders. P. denticulata and P. macrophylla were the most cited plant species with higher use reports such as 104 and 93, respectively. One or more extracts of different parts of Primula species showed a noteworthy antibacterial activity against one or more tested bacteria.ConclusionThis study provides novel information regarding several categories of traditional uses and antibacterial activity of Primula species in Azad Kashmir, Western Himalaya. The need for novel and more effective drugs derived from natural products is more important than ever, making future studies on herbal remedies both justified and urgently required.     

New adapiform primate of Old World affinities from the Devil's Graveyard Formation of Texas

Most adapiform primates from North America are members of an endemic radiation of notharctines. North American notharctines flourished during the Early and early Middle Eocene, with only two genera persisting into the late Middle Eocene. Here we describe a new genus of adapiform primate from the Devil’s Graveyard Formation of Texas. Mescalerolemur horneri, gen. et sp. nov., is known only from the late Middle Eocene (Uintan) Purple Bench locality. Phylogenetic analyses reveal that Mescalerolemur is more closely related to Eurasian and African adapiforms than to North American notharctines. In this respect, M. horneri is similar to its sister taxon Mahgarita stevensi from the late Duchesnean of the Devil’s Graveyard Formation. The presence of both genera in the Big Bend region of Texas after notharctines had become locally extinct provides further evidence of faunal interchange between North America and East Asia during the middle Eocene. The fact that Mescalerolemur and Mahgarita are both unknown outside of Texas also supports prior hypotheses that low-latitude faunal assemblages in North America demonstrate increased endemism by the late middle Eocene.     

Was the Early Eocene proboscidean Numidotherium koholense semi-aquatic or terrestrial? Evidence from stable isotopes and bone histology

The Early Eocene deposits of El Kohol, Algeria, have yielded numerous remains of Numidotherium koholense, one of the most primitive and oldest known proboscideans in Africa. The Upper Eocene proboscideans of the Fayum locality (Egypt), Barytherium sp. and Moeritherium sp., were recently interpreted as aquatic or semi-aquatic, according to the stable isotopic compositions (δ¹³C and δ¹⁸O) of their tooth enamel. These data led us to reinvestigate the adaptations of N. koholense. Stable isotopic analysis and observations of histological sections of its long bones reveal that it was essentially terrestrial. According to its position within the phylogenetic tree of Eocene proboscideans, the adaptation to semi-aquatic life appears to have evolved independently in different lineages of Middle and Upper Eocene proboscideans during their adaptive radiation in Africa. Moreover, these new results reopen the debate about the hypothesis that Eocene to Recent proboscideans are derived from semi-aquatic ancestors.     

A new species of Nelumbo from South China and its palaeoecological implications

A new species of Nelumbo Adanson is described from the Eocene of the Changchang Basin, Hainan Island, South China. This is the first comprehensive report on a fossil Nelumbo species from the Eocene of the Changchang Basin, Hainan Island. The co-occurrence of fruits, tubers, rhizomes with numerous adventitious roots, leaves, and receptacles indicates that the plants grew where they are preserved. These specimens, combined with palynological assemblage and other macrofossils, indicate a tropical or subtropical humid climate in the Changchang Basin from the late early Eocene to early late Eocene.     

Squamate reptiles from the middle Eocene of Lissieu (France). A landmark in the middle Eocene of Europe

In Europe, faunas of squamates (lizards and snakes) from the middle Eocene are very poorly known, with the exception of those from the level MP 16 (latest middle Eocene). From the MP 11-MP 15 interval, squamates were previously reported only from Messel (MP 11, earliest middle Eocene) and from the untere and obere Mittelkohle of Geiseltal (MP 12 and MP 13 respectively) in Germany. The present report describes the middle Eocene assemblage of squamates from Lissieu (France), the first fauna reported from the level MP 14. Whereas fossils from Messel and Geiseltal are mostly articulated skeletons, fossils from Lissieu are represented by disarticulated bones; such fossils may be more easily compared to those from other Cenozoic localities, in which bones are almost always disarticulated. The fauna from Lissieu is more diverse than those from the Geiseltal sites and approximately as diverse as that from Messel as they are presently known; it is comprised of 17 distinct taxa. These taxa cannot be all identified to the species or genus level. They belong to iguanids, gekkonids, lacertids, anguids, thecoglossan platynotans, ophidians incertaesedis, boids, ?tropidophiines, “tropidophiids” incertaesedis, booids incertaesedis, and perhaps russellophiids. The fauna includes several new taxa but only a presumed tropidophiine snake may be named on the basis of the available material. The fauna from Lissieu is a mixture of taxa restricted to the middle Eocene and taxa known from older or younger levels. Taxa shared by Lissieu and the few other localities from the middle Eocene of Europe are rare. This fauna from Lissieu represents a stratigraphical landmark for the middle Eocene.     

Remains of sea turtles from the Ikovo locality (Lugansk Region, Ukraine; Middle Eocene)

Fragmentary remains of sea turtles (Cheloniidae sensu lato: Argillochelys sp., Puppigerus nessovi Averianov, 2005, and Cheloniidae gen. indet.) from the Ikovo locality (Lugansk Region, Ukraine; Lower Lutetian, Middle Eocene) are described. The genera Argillochelys and Puppigerus are recorded for the first time in Eastern Europe. The turtle assemblage from Ikovo is similar at the generic level to West European assemblages (Belgium, Great Britain) of approximately the same age (Lower-Middle Eocene). In the presence of P. nessovi, the Ikovo assemblage is similar to that from the Middle Eocene Dzheroi 2 locality (Uzbekistan).     

L’origine et l’histoire évolutive des Cétacés

Cetaceans are the most highly modified mammals. They originate among terrestrial ariodactyles during the Early Eocene. The oldest known cetacean is Pakicetus, a terrestrial and cursorial taxon of the Early Eocene (50 Ma), which entered the water in search for food or, possibly, to protect its skin from the sun. A few million years later, Ambulocetus is an amphibious cetacean capable of moving on land but also an agile swimmer using its hind limbs for propulsion. Ambulocetus was a formidable predator with powerful teeth. The nares of Pakicetus and Ambulocetus were anteriorly placed, at the apex of the snout. During the Late Eocene, there appeared the first strictly aquatic cetaceans, the Basilosauridae. Their hind limbs are totally atrophied and are not functional. The nares are on the dorsal face of the rostrum on the anterior third of the skull. From that time, the way toward modern cetaceans was opened; the oldest mysticetes are from the Latest Eocene and the oldest odontocetes from the Early Oligocene.